Issues with mirroring an image to the 2nd monitor (TV).

Got two comps with Xub 16 both outputting to same TV as 2nd monitor with diff results.

Comp Monitor:
-Asus
-native res 1920x1080 in 60Hz

TV:
-LG
-native res 1920x1080 in 60Hz

Comp1:
-updated from Xub 14 to 16
-ATI GPU
-connected to TV through HDMI
-detects correct TV brand but incorrect screen size as 7"
-detects correct res on both monitors
-after selecting mirroring in Display, correctly clones the image to TV

Comp2:
-Xub 16 new installation
-nVidia GPU
-connected to TV through VGA
-identifies TV only as digital display (no brand or screen size)
-incorrectly assesses TV's max res as 1024x768
-outputs an image to TV even without selection of mirroring
-after selecting mirroring in Display, downgrades the res of comp monitor to 1024x768

Questions:
1. Is the failure to mirror/clone the image correctly on Comp2 most likely caused by an issue with the driver for the nVidia GPU or am I just overlooking some basic setting somewhere?
2. Can the cable used to connect to TV: HDMI, VGA or S-Video have an impact on the correct detection of res on TV?
3. If it is the driver, am I likely to find a working alternative driver (where, how, etc.) or would it be simpler to try to find a used ATI GPU?